The present invention concerns improved methods and apparatus for forming undulated wire coils that are placed into the cores of dynamo electric machine components. In particular, the invention concerns improved methods and apparatus for controlling the direction of deposit for the turns of a wire coil and for positioning the leads of the coil. “Direction of deposit” refers to the direction that winding proceeds along the axis about which the coil is wound. “Direction of deposit” does not refer to whether wire is deposited going clockwise or counter-clockwise about the just-mentioned axis. Rather, “direction of deposit” refers to which direction along (i.e., substantially parallel to) the just-mentioned axis successive turns of wire are deposited as winding proceeds. The general background of the invention is provided in Barrera U.S. Pat. No. 5,881,778, and Bonnacorsi et al. U.S. Pat. No. 6,386,243, which are hereby incorporated by reference herein in their entireties.
Selective positioning of wire leads in a coil is generally done to protect the leads from interfering with operation and becoming damaged. For example, the leads may be selectively positioned away from a portion of the core that will be adjacent to a relatively moving component in the finished and operating dynamo-electric machine. According to the prior art, such positioning is generally achieved by controlling the final lead of the wire to produce a desired position for the lead when placed within the coil. Conventionally, a single layer of coils placed at the radially innermost portion of the core may have selectively positioned wire leads that are placed away from the center of the core.
One method for reducing the opportunity for interference from wire leads is to reduce their frequency within the core. To this end, multiple wire coil portions may be formed from a continuous wire segment that has only a single initial lead and a single final lead. In the prior art, each coil portion is formed by winding wire turns in a single direction of deposit, with the resulting coil having an initial lead and a final lead at radially opposite locations when placed on the core. This arrangement of the wire leads in the continuous wire portions produces similar interference problems as in the independent wire coils, where the wire leads are exposed to the radially inner aperture and the radially outer contour of the core.